1. Field of the Invention
The invention relates to a rotary vibration damper.
2. Discussion of the Prior Art
A rotary vibration damper is known, for example, from German Reference DE 34 29 373, and includes a rotor and a stator equipped with vanes, which form the work chambers of the rotary vibration damper. During a spring movement of a wheel, the rotor and the stator rotate relative to each other, so that, in alternating fashion, one work chamber is enlarged in its volume and another is reduced.
Choke valves are arranged in the vanes and permit the pressurized damping medium to overflow from the work chamber that is becoming smaller into the enlarging work chamber. To avoid hydraulic blocking, the rotary vibration damper must therefore have at least half as many choke valves as rotor vanes or stator vanes. Moreover, although the number of valves is a problem, what is far more important is that all of the choke valves used must have as identical as possible a damping characteristic, because different pressure levels in the work chambers necessarily result in transverse forces between the rotor and the stator. Such forces can only be controlled by means of an expensive bearing.